A. V. Glushkov

Muons in extensive air showers of energies E0=1016.6–1019.8 eV

Data on muons with the threshold energy Eμ≈1.0×secθ GeV in extensive air showers of energies E0≥4×1016 eV measured on the Yakutsk and Akeno arrays are jointly analyzed. The results are compared with the calculations by the quark-gluon-string model with jets. It is shown that this model does not contradict the data measured for energies E0≤1018 eV on both arrays under the assumption that the primary particle composition differs from the composition where heavy nuclei dominate over protons. Experimental data for energies E0≥3×1018 eV indicate that the shower development differs from that predicted by the quark-gluon-string model with jets.

Electrons and muons in extensive air showers of energies E0≥3×1017 eV: Yakutsk array data and QGSJET model

The results obtained from an analysis of the 1974–1998 Yakutsk array data on muons with threshold energy Eμ ≈ 1.0 × secθ GeV and on all charged particles (electrons and muons) in extensive air showers (EAS) are reported and compared with the results of calculations based on the model of quark-gluon strings with jets. For energies of E0≤3×1018 eV and zenith angles of θ≤45°, the results of the model calculations are consistent with the measured properties of the showers, while, for higher energy EASs, there are considerable discrepancies, which are probably due to the change in the development of the shower cascade in the region E0≥3×1018 eV.

Spectroscopy of cooperative laser–electron nuclear effects in multiatomic molecules

A consistent quantum approach to calculating the electron–nuclearu2009γu2009transition spectra (a set of vibration–rotational satellites in a molecule) of a nucleus in the multiatomic molecules is proposed and generalizes the well-known Letokhov–Minogin model. Estimates of the vibration–nuclear transition probabilities in a case of the emission and absorption spectrum of nucleus 188Os in the molecule of OsO4 and nucleus 191Ir in the molecule IrO4 are presented.

Nonstationary phenomena in cosmic rays with E 0 ≤ 10 18 eV according to the data of the Yakutsk EAS array

The energy spectrum of cosmic rays and the fraction of muons with the threshold 1.0secθ GeV in the total number of charged particles in extensive air showers with energy E0 ≥ 1017 eV according to Yakutsk array data collected during 35 years of its continuous operation in 1978–2012 have been analyzed. It has been shown that these characteristics are noticeably different in different time periods. Before 1996, the integral intensity of the spectrum at E0 = 1017 eV varied near one stable position and then began to increase. It increased by (45 ± 5)% in seven years and, then, began to decrease. This phenomenon was accompanied a similar change in the fraction of muons and was caused by a significant increase in the average weight of the chemical composition of cosmic rays after 1996 as compared to preceding years.

QED theory of radiation emission and absorption lines for atoms in a strong laser field

The consistent approach to the atom–realistic laser field interaction is presented, which is based on the quantum electrodynamics (QED) and the Gell–Mann and Low S-matrix formalism.. The method is applied for studying the multi-photon resonance width and shift in the atoms of H and Cs in a laser pulse.

Dependence of the energy spectrum of UHE cosmic rays on the latitude of an extensive air shower array

Several energy spectra of cosmic rays with energies E0 ≥ 1017 eV measured at the Yakutsk EAS, AGASA, Haverah Park, HiRes, Auger, and SUGAR arrays are considered. It is shown that the fairly good mutual agreement of the spectrum shapes can be achieved if the energy of each spectrum is multiplied by a factor K specific for each spectrum. These factors exhibit a pronounced dependence on the latitude of the above-mentioned arrays.

Yakutsk EAS array data on the variations in intensities of the highest energy cosmic rays

The results of analysis of arrival frequency of cosmic rays with energies E0≥4×1017 eV are presented based on the data collected on the Yakutsk array during its 24 years of continuous operation (1977–2000). It is shown that the intensity of cosmic rays is variable. At E0≤(3−5)×1018 eV, the (2–3)-month data show many deviations by (3–4)σ from the mean level. At E0≥1019 eV, the intensities steadily decrease, on the average, by 1.5 times during the time period considered.

Theoretical spectroscopy of autoionization resonances in spectra of lanthanide atoms

A theoretical study of the autoionization resonances in the spectra of lanthanide atoms (ytterbium) was carried out within the relativistic many-body perturbation theory and the generalized relativistic energy approach (the Gell-Mann and Low S-matrix formalism). The accurate results on the autoionization resonance energies and widths in ytterbium are presented with correctly accounting for the exchange correlation and relativistic corrections and are compared with the other available theoretical and experimental data.

Clusters in the arrival directions of 2×1017-eV cosmic rays detected at the Yakutsk EAS array

Arrival directions of (1.3–4)×1017-eV cosmic rays detected for zenith angles θ≤53° at the Yakutsk array from 1974 to 2001 are analyzed. These directions exhibit numerous clusters correlating with the supergalactic plane.

Electron-β-Nuclear Spectroscopy of Atoms and Molecules and Chemical Bond Effect on the β-Decay Parameters

We discuss the cooperative electron β-nuclear processes in atoms and molecules, including the excitation, ionization, electronic rearrangement, induced by the nuclear reactions and β-decay. The relativistic many-body perturbation theory (PT) with the optimized Dirac–Kohn–Sham (DKS) zeroth approximation is used to calculate the β-decay parameters for a number of allowed (superallowed) transitions (33P–33S, 241Pu–241Am, etc.) and study a chemical bond effect on β-decay parameters. A few factors are taken into account: changing the integration limits in the Fermi function integral, energy corrections for different chemical substances and the possibility of the bound β-decay or other decay channels. We studied the electronic rearrangement induced by nuclear transmutation in the β-decay ({}_{rm{2}}^{rm{6}} {rm{He}}_{rm{4}} to ({}_3^6 {rm{Li}}_{rm{3}}^{rm{ + }} )^* + e^ - + bar nu _e ). The half-life period T 1 / 2 for β-decay of tritium atom (ion) has been estimated while taking into account the bound β-decay channel and some other accompanying effects. The estimated values of T 1 / 2 for the tritium β-decay and free triton decay are (T 1 / 2)a=12.26 years (correction due to the electron-atomic effects (Δ T 1 / 2/T 1 / 2) a =0.82%) for the tritium atom and (T 1 / 2) t =12.36 years for the triton decay. These data are in physically reasonable agreement with experimental data. We first present the value T 1 / 2 in a case of the β-decay in the halogen-containing molecular tritium (3HCl): (T 1 / 2) m =12.28 years (3HCl) and the correction due to the chemical bond effect is (Δ T 1 / 2) am =0.024 (i.e. 0.20%).